This invention relates to a filter for x-ray examining devices.
A radiographic apparatus comprises, as well known in the art, as its fundamental components, a source of an ionizing and penetrative radiation, normally an x-ray tube, an object plane in which the object, or patient, to be radiographed is positioned, and an image plane on the opposite side of the object plane relative to the radiation source, in which image plane an image recording medium or device is disposed. The image recording medium may be a film sensitive to ionizing radiation, a fluorescent display screen or an electronic image amplifier.
When exposing chest x-rays, if the source of radiation is kept at a level that will provide a proper viewing density to the lungs, the level of radiation to provide acceptable exposure of parts of the body that are composed of dense tissue, e.g. the spine and the heart, will be insufficient.
It is an object of this invention to provide a means for maintaining an acceptable density level of x-ray exposure for the lungs while allowing a higher level of x-ray exposure in the heart and mediastinum areas of the body.
It is another object of this invention to provide a means for permitting a higher level of x-ray exposure in the heart and mediastinum areas of the body wherein such means can be easily adjusted for variations in (a) radiographic apparatus, (b) distance of radiation source from the patient, and (c) the physiology of specific patients.